class_docstr: A regular expression-based tokenizer at word boundary.
  This tokenizer default to support MegaMolBART.
  <https://catalog.ngc.nvidia.com/orgs/nvidia/teams/clara/models/megamolbart>
docstr: Infers files or update if given.
docstr_tok: ["Infers","files","or","update","if","given","."]
code: def _get_regex_vocab_files(self, regex_file=None, vocab_file=None):
      """
      Infers files or update if given.
      """
      regex_file = regex_file or self.regex_file
      if not regex_file:
          raise ValueError(f"regex_file must be specified")
  
      vocab_file = vocab_file or self.vocab_file
      # try to infer vocab_file from regex_file
      if not vocab_file:
          vocab_file = os.path.splitext(regex_file)[0] + ".vocab"
  
      self.regex_file = regex_file
      self.vocab_file = vocab_file
  
      return regex_file, vocab_file
  
imports: import os
  import re
  from typing import Optional
  import pandas
  from nemo.collections.common.tokenizers.char_tokenizer import TokenizerSpec
  from nemo.utils import logging
label_desc: Use image node_id 18 for calling the RegExTokenizer obj's underlying member method code with example usage: obj._get_regex_vocab_files(regex_file, vocab_file) and returns: regex_file,  vocab_file